Multishell EXAFS Fitting Analysis of a Compositionally Precise Thiolate-Gold Nanocluster

2014 ◽  
Vol 1655 ◽  
Author(s):  
Daniel M. Chevrier ◽  
Amares Chatt ◽  
Peng Zhang ◽  
Chenjie Zeng ◽  
Rongchao Jin
Keyword(s):  
Structural Information ◽  
Gold Nanoclusters ◽  
Gold Nanocluster ◽  
Experimental Conditions ◽  
X Ray ◽  
Metal Metal ◽  
Ligand Interactions ◽  
Novel Applications ◽  
X Ray Absorption ◽  
Metal Ligand

ABSTRACTThiolate-gold nanoclusters exhibit unique optical, magnetic and chiral properties, which are attractive for novel applications in nanotechnology. A fundamental challenge facing these nanomaterials is being able to study and understand their physical properties in various experimental conditions. To overcome this, extended X-ray absorption fine structure (EXAFS) spectroscopy can be employed to probe the Au local structure of thiolate-gold nanoclusters in a variety of conditions, providing valuable structural information from multiple bonding environments (i.e. metal-metal and metal-ligand interactions). This study discusses a methodology for conducting a multishell EXAFS fitting analysis that can be implemented for thiolate-gold nanocluster systems. Specifically, experimental and simulated EXAFS data for Au36(SR)24 nanoclusters are examined with a total of 5 scattering paths fitted to the experimental data.

Bonding properties of thiolate-protected gold nanoclusters and structural analogs from X-ray absorption spectroscopy

2015 ◽  
Vol 4 (2) ◽  
Author(s):  
Daniel M. Chevrier ◽  
Rui Yang ◽  
Amares Chatt ◽  
Peng Zhang
Keyword(s):  
Gold Nanoparticles ◽  
Absorption Spectroscopy ◽  
Gold Nanoclusters ◽  
Gold Surface ◽  
Experimental Conditions ◽  
X Ray ◽  
Gold Core ◽  
Specific Analysis ◽  
Bonding Properties ◽  
X Ray Absorption

AbstractSubnanometer, atomically precise thiolate-protected gold nanoclusters represent an important advancement in our understanding of thiolate-protected gold nanoparticles and thiolate-gold chemistry. Aside from being a link between larger gold nanoparticles and small gold complexes, gold nanoclusters exhibit extraordinary molecule-like optical, electronic, and physicochemical properties that are promising for next-generation imaging agents, sensing devices, or catalysts. The success in elucidating a number of unique thiolate-gold surface and gold core structures has greatly improved our understanding of thiolate-gold nanoclusters. Nevertheless, monitoring the structural and electronic behavior of thiolate-protected gold nanoclusters in a variety of media or environments is crucial for the next step in advancing this class of nanomaterials. Not to mention, there are a number of thiolate-protected gold nanoclusters with unknown structures or compositions that could reveal important insights on application-based properties such as luminescence or catalytic activity. This review summarizes some of the recent contributions from X-ray absorption spectroscopy (XAS) studies on the intriguing bonding properties of thiolate-protected gold nanoclusters and some structural analogs. Advantages from XAS include a local structural, site- and element-specific analysis, suitable for ultra-small particle sizes (1–2 nm), along with versatile experimental conditions.

Manganese K-Edge X-Ray Absorption Spectroscopy as a Probe of the Metal–Ligand Interactions in Coordination Compounds

2011 ◽  
Vol 51 (1) ◽  
pp. 680-687 ◽  
Author(s):  
Michael Roemelt ◽  
Martha A. Beckwith ◽  
Carole Duboc ◽  
Marie-Noëlle Collomb ◽  
Frank Neese ◽  
...  
Keyword(s):  
Absorption Spectroscopy ◽  
Coordination Compounds ◽  
X Ray ◽  
Ligand Interactions ◽  
X Ray Absorption ◽  
Metal Ligand

Ligand K-edge X-ray absorption spectroscopic studies: metal-ligand covalency in transition metal tetrathiolates

1997 ◽  
Vol 263 (1-2) ◽  
pp. 315-321 ◽  
Author(s):  
Kendra Rose Williams ◽  
Britt Hedman ◽  
Keith O. Hodgson ◽  
Edward I. Solomon
Keyword(s):  
Transition Metal ◽  
Spectroscopic Studies ◽  
X Ray ◽  
X Ray Absorption ◽  
Metal Ligand

scholarly journals Extracting structural information of Au colloids at ultra-dilute concentrations: identification of growth during nanoparticle immobilization

2019 ◽  
Vol 1 (7) ◽  
pp. 2546-2552 ◽  
Author(s):  
George F. Tierney ◽  
Donato Decarolis ◽  
Norli Abdullah ◽  
Scott M. Rogers ◽  
Shusaku Hayama ◽  
...  
Keyword(s):  
Absorption Spectroscopy ◽  
Structural Characterization ◽  
Structural Information ◽  
Particle Growth ◽  
Au Nanoparticle ◽  
X Ray ◽  
Colloidal Au ◽  
X Ray Absorption ◽  
Au Colloids

This paper describes the structural characterization of ultra-dilute colloidal Au nanoparticle solutions using X-ray absorption spectroscopy (XAS) and the particle growth during immobilization.

scholarly journals Solving the Structure and Dynamics of Metal Nanoparticles by Combining X-Ray Absorption Fine Structure Spectroscopy and Atomistic Structure Simulations

2019 ◽  
Vol 12 (1) ◽  
pp. 501-522 ◽  
Author(s):  
J. Timoshenko ◽  
Z. Duan ◽  
G. Henkelman ◽  
R.M. Crooks ◽  
A.I. Frenkel
Keyword(s):  
Fine Structure ◽  
Three Dimensional ◽  
Dimensional Structure ◽  
Structural Refinement ◽  
Particle Structure ◽  
X Ray ◽  
Structure And Dynamics ◽  
Absorption Fine ◽  
Metal Metal ◽  
X Ray Absorption

Extended X-ray absorption fine structure (EXAFS) spectroscopy is a premiere method for analysis of the structure and structural transformation of nanoparticles. Extraction of analytical information about the three-dimensional structure and dynamics of metal–metal bonds from EXAFS spectra requires special care due to their markedly non-bulk-like character. In recent decades, significant progress has been made in the first-principles modeling of structure and properties of nanoparticles. In this review, we summarize new approaches for EXAFS data analysis that incorporate particle structure modeling into the process of structural refinement.

Accuracy in quantitative phase analysis of mixtures with large amorphous contents. The case of stoneware ceramics and bricks

2014 ◽  
Vol 47 (3) ◽  
pp. 835-846 ◽  
Author(s):  
Alessandro F. Gualtieri ◽  
Vincenzo Riva ◽  
Andrea Bresciani ◽  
Stefano Maretti ◽  
Marco Tamburini ◽  
...  
Keyword(s):  
Phase Analysis ◽  
Internal Standard ◽  
Quantitative Phase Analysis ◽  
Experimental Conditions ◽  
X Ray ◽  
Quantitative Phase ◽  
Factor Method ◽  
Counting Statistics ◽  
First Time ◽  
X Ray Absorption

For the first time, this work inspects the accuracy of quantitative phase analysis of both crystalline and amorphous components of stoneware tiles and bricks. A number of variables were considered: the nature of the internal standard, experimental conditions and counting statistics. The so-calledG-factor method has also been applied. The results of the X-ray powder diffraction analysis have been compared with the results obtained with optical microscopy and image analysis. Only the mixtures spiked with corundum and silicon yielded accurate weight estimates of the amorphous fraction, whereas the use of highly X-ray absorbing internal standards (such as fluorite, rutile and zincite) resulted in gross underestimations. In fact, microabsorption effects are found to drastically reduce the accuracy of the results when standards with linear X-ray absorption coefficients higher than 100 cm−1are employed. It was found that very low counting statistics reduced the calculated amorphous fractions in both bricks and stoneware tiles owing to partial masking of the major peak of the internal standard, namely corundum. The application of theG-factor method to the systems investigated was also evaluated. The results are poorer than those obtained using the internal standard.

Structure of Two Disordered Molybdates, Li2MoIVO3 and Li4Mo3 IVO8, from Total Neutron Scattering

1997 ◽  
Vol 53 (4) ◽  
pp. 604-612 ◽  
Author(s):  
S. J. Hibble ◽  
I. D. Fawcett ◽  
A. C. Hannon
Keyword(s):  
Neutron Scattering ◽  
Rietveld Analysis ◽  
Total Neutron ◽  
Bragg Scattering ◽  
Pair Correlations ◽  
X Ray ◽  
Metal Metal ◽  
X Ray Absorption ◽  
Average Structures ◽  
Insight Into

The structures of the disordered lithium molybdates Li2MoO3 and Li4Mo3O8 have been investigated using total neutron scattering from polycrystalline powders. Rietveld analysis of the Bragg scattering is used to determine the average structures. Shortcomings in this method of analysis are demonstrated by comparing the total correlation function, T(r), determined from total neutron scattering, with those calculated from the structures determined from Rietveld analysis. Much more satisfactory models for these materials are derived from the structurally related ordered material LiZn2Mo3O8, using information from Mo K-edge extended X-ray absorption fine-structure spectroscopy (EXAFS). These models include metal–metal-bonded Mo3O13 clusters [d(Mo—Mo) = 2.58 Å in Li2MoO3 and 2.56 Å in Li4Mo3O8] not present in the average structure determined from Rietveld analysis [d(Mo—Mo) = 2.88 Å in Li2MoO3]. In contrast to EXAFS studies neutron diffraction yields information on all the pair correlations in the material, not merely those involving molybdenum, and allows, for example, the location of lithium. Remaining discrepancies between our models and the experimental T(r)'s give an insight into the disorder in the two materials.

Ligand K-edge x-ray absorption spectroscopic studies: metal-ligand covalency in a series of transition metal tetrachlorides

1995 ◽  
Vol 117 (8) ◽  
pp. 2259-2272 ◽  
Author(s):  
Susan E. Shadle ◽  
Britt Hedman ◽  
Keith O. Hodgson ◽  
Edward I. Solomon
Keyword(s):  
Transition Metal ◽  
Spectroscopic Studies ◽  
X Ray ◽  
X Ray Absorption ◽  
Metal Ligand
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